Rev rise when fan runs

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GRUVBB
I am quitting my job and going 5-ing
I am quitting my job and going 5-ing
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Joined: Sat May 04, 2013 4:50 pm
Location: Fastlane to Ak

Rev rise when fan runs

Post by GRUVBB » Sun Nov 10, 2013 8:24 pm

Car developed a new anomily today. Noticed this afternoon when i turned the heater fan on that the revs increased by 1000 rpm.... I am aware that the revs will increase when a load comes on the alternator. It has never increased by this much. It is same on all speed settings of fan. Even once car has warmed up to running temp. The car idles nicely at about 800 rpm. When fan runs it is up about 2000. The revs do drop back after about 10 seconds but are still,higher than they used to run at at about 1400.
If i turn headlights on without fan the revs remain low. It only appears to be the fan affecting it. Hope its not shorting out and pulling excessive amps.
I will be checking fan belt tension tomorrow. Will also check battery charge voltage and terminations.
Does anyone have any other ideas or things to look out for :?: thanks in advance.

SLYDIT
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Keep calm, Forum Moderator here.
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Post by SLYDIT » Sun Nov 10, 2013 9:01 pm

That's a good start. Put your volt meter on the alt out put and run the fan. Also if your air con button is on it will bring on the second rad fan and idle up too. The air con only kicks in when the fan turns on so check that
RED '90 TURBO.
SCARING PRIUS DRIVERS SINCE 2002

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